package cn.itcast.demo1;

import java.util.HashMap;
import java.util.Map;

public class Test {
    public static void main(String[] args){
        Map<Integer,Student> map = new HashMap<>();
        Student s1 = new Student("张三",23);
        Student s2 = new Student("李四",25);
        Student s3 = new Student("王五",27);
        Student  stu1 = map.put(1,s1);
        System.out.println("stu1: "+ stu1);


        System.out.println(map);

    }

}
